Field of the Invention
The present invention relates to a liquid crystal display device (LCD), and more particularly, to an LCD including a nanocapsule layer and method for manufacturing the same.
Discussion of the Prior Art
Recently, facing information society, display field of displaying electric information signals has been rapidly advanced, and flat display devices having high performances of thin profile, lightweight and low power consumption have been developed and used. Among these flat display devices, liquid crystal display devices (LCDs) are widely used.
FIG. 1 is a cross-sectional view illustrating an LCD according to the prior art.
Referring to FIG. 1, the LCD includes a liquid crystal panel 10 including an array substrate, a color filter substrate and a liquid crystal layer 50 between the array substrate and the color filter substrate, and a backlight unit 60 below the liquid crystal panel 10. A first substrate 2 referred to as the array substrate includes a pixel region P, and on an inner surface of the first substrate 2, a thin film transistor T is in each pixel region P and connected to a pixel electrode P in each pixel region P.
On an inner surface of a second substrate 4 referred to as the color filter substrate, a black matrix 32 is formed in a lattice shape surrounding the pixel region P to cover a non-display element such as the thin film transistor T and expose the pixel electrode 28.
Red, green and blue color filters 34 are formed in the lattice shape corresponding to the respective pixel regions P, and a common electrode 36 is formed on the black matrix 32 and the color filters 34.
First and second polarizing plates 20 and 30 are attached onto outer surfaces of the first and second substrates 2 and 4, respectively.
First and second alignment layers 31a and 31b are formed between both the pixel electrode 28 and the common electrode 36, and the liquid crystal layer 50. The first and second alignment layers 31a and 31b are rubbed and align liquid crystal molecules.
A seal pattern 70 is formed between and along peripheral regions of the first and second substrates 2 and 4 and prevents leakage of the liquid crystal.
The backlight unit 60 supplies light to the liquid crystal panel 10. The backlight unit 60 is categorized into a sidelight type and a direct type.
The sidelight type backlight unit has a light source on at least one side of a light guide panel. The direct type backlight unit has a light source below the liquid crystal panel 10.
The sidelight type backlight unit has advantages of simple manufacturing, thin profile, lightweight, and low power consumption.
FIG. 2 is a cross-sectional view illustrating the LCD including the backlight unit according to the prior art.
Referring to FIG. 2, the backlight unit 60 includes a light guide plate 23, a light emitting diode (LED) assembly 29 along a side of the light guide plate 23, a reflector 25 below the light guide plate 23, and at least one optical sheets 21 on the light guide plate 23.
The LED assembly 29 includes a plurality of LEDs 29a, and a printed circuit board (PCB) 29b on which the LEDs 29a are mounted.
Light emitted from the LED assembly 29 enters into the light guide plate 23, then is refracted toward the liquid crystal panel 10, then is processed into light of high quality and uniform brightness passing through the optical sheet 21, and then enters into the liquid crystal panel 10. Accordingly, the liquid crystal panel 10 displays images.
A portion of the light emitted from the backlight unit 60 is absorbed and reflected by the first polarizing plate 20 and thus is lost, which may be about 50% of all the light emitted from the backlight unit 60. Further, light is absorbed and reflected while passing through the first and second substrates 2 and 4 and the liquid crystal layer (50 of FIG. 1), and thus an additional portion of the light is lost. As such, the LCD has disadvantage in brightness compared with other types of flat display displays.
Moreover, the LCD has slow response speed, and thus display quality is reduced due to afterimage.
Moreover, the LCD requires many production processes, and thus production efficiency is reduced.
The above LCD using the backlight unit 60 is referred to as a transmissive type LCD, in which the backlight unit 60 consumes about two-third or more of a total power of the LCD. To solve this problem, a reflective type LCD not using a backlight unit is suggested.
However, in the reflective type LCD, light leakage is easily caused by an external force, and thus display quality is reduced. Moreover, the reflective type LCD also requires many production processes, and thus production efficiency is reduced.